One of the rules I liked from the /r/games community was one of the rules you mentioned here: “Use the same titles as the article itself.” I think all the rules you mentioned here are definitely good ground rules as well.
Personally, I would also like to see people adopting the body portion of Lemmy posts to summarize the article, or quote a meaty part of the article; but that could also be used for misleading purposes, so I’m not sure if that’s a good idea without some level of oversight.